I/Q imbalance cancellation algorithm based on affine projection adaptation

Abstract

The invention provides an I / Q imbalance cancellation algorithm based on affine projection adaptive filtering, relating to a blind cancellation algorithm without training sequences. The whole cancellation process is modeled as an adaptive filtering mode, a wide linear model is used as the filtering structure prototype of a neutralizing filter, the restoration the 'moderation' of signals disturbed by I / Q imbalance is taken as the goal, and an adaptive process of the filter is deduced based on the principle of affine projection adaptation, which means that an update iteration rule of filter tap weights is obtained. Additionally, combined with some improvements of I / Q imbalance situations, the algorithm can be applied to engineering practices; and finally, the overall operation flow of the cancellation algorithm can be obtained; and computer simulation results can verify that the impact of the I / Q imbalance on the signals can be effectively canceled by the algorithm, and meanwhile, compared with a traditional cancellation algorithm, the algorithm provided by the invention has a faster convergence rate and more stable MSE performance.

Description

technical field [0001] The invention relates to the technical field of digital signal processing, in particular to an I / Q imbalance cancellation method in a direct frequency conversion receiver. Background technique [0002] Modern wireless transceiver structures generally adopt the combination of direct frequency conversion structure and low-cost wireless electronic technology, but there are certain problems in the specific implementation of this method, mainly due to the physical limitations and component changes of the electronic equipment used. One of our main concerns is the interference caused by I / Q imbalance. The I / Q imbalance mainly comes from the quadrature mixing stage of the local oscillator. The specific meaning is the non-ideal matching of the amplitude gain and phase between the two signal branches. The consequence is that it will damage the image interference suppression ability of the direct conversion transceiver. . [0003] The problem of compensation fo...

AI Technical Summary

Problems solved by technology

Although traditional data-assisted non-blind algorithms can achieve considerable performance by using training sequences, they are usually accompanied by a significant increase in the complexity of channel equalization and frequency offset estimation, and require more prior knowledge. Therefore, there is still room for improvement in algorithm efficiency.

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